1. Field of the Invention
This invention relates to improvements in fittings used to drive spools of motion picture film.
2. Description of the Prior Art
Prior art film drives commonly use a spindle which is square or has ears projecting therefrom to engage and drive a spool mounted thereon. Where spools are of large diameters, stresses on the ears and corners of the spindle become excessive and breakage or slippage may result. Drive pins offset from the axis of the spindle have been used to avoid the breakage and slippage problem, but international standards have been lacking and consequently different designs have been employed for placement of the offset driving pin. Some drive pins are radially offset from a corner of the square spindle, while others are on a perpendicular to a side of the spindle. Spools and spool drives designed in one configuration are not adaptable to or useable with drives or spools designed in the other configurations. Drive systems convertible from, e.g. 35mm to 16mm film spools must also have means for converting from one drive pin location position to the other.